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Calendar of Physics Talks Vienna
| Covariant Lagrangians for (twisted) self-duality equations of (non-)chiral p-forms and their Abelian interactions |
| Speaker: | Karapet Mkrtchyan (Imperial College, London) |
| Abstract: | We present a covariant Lagrangian formulation for p-form fields in Minkowski spaces of arbitrary dimensions that treat electric and magnetic degrees of freedom on equal footing. This formulation allows the inclusion of arbitrary abelian self-interactions. In d=4k+2,we cover all abelian self-interactions of a chiral (self-dual) 2k-form, the most interesting example being d=6 (we also comment on d=2 and 10), where the general abelian self-interactions are parametrized by a function of one variable. For d=4k, we cover all abelian self-interactions of (2k-1)-forms, including those with SO(2) duality symmetry. For d=4, we give a simple democratic actionfor arbitrary non-linear electrodynamics involving an arbitrary function of two variables and its duality symmetric subclass manifesting SO(2)symmetry, parametrized by a function of one variable. |
| Date: | Tue, 09.05.2023 |
| Time: | 14:00 |
| Duration: | 60 min |
| Location: | TU Sem.R. DA gruen 05 (Freihaus, TU Wien, Wiedner Hauptstrasse 8) |
| Contact: | S. Fredenhagen, D. Grumiller, E. Battista, R. Ruzziconi |
| Production of matter in the early Universe |
| Speaker: | Yann Mambrini (IJCLab, Orsay) |
| Abstract: | I will present in this seminar recent works concerning the production of particles in the earliest stage of the Universe,
between the preheating phase and the reheating time.
I will insist on the subtleties of backreactions from scattering of the inflaton and apply it to the mechanism to the
dark matter production in minimal extensions of the Standard Model, especially gravitational production.
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| Date: | Tue, 09.05.2023 |
| Time: | 16:15 |
| Duration: | 60 min |
| Location: | Fakultaet fuer Physik, Erwin Schroedinger-HS, Boltzmanngasse 5, 5. Stock |
| Contact: | A. Hoang, J. Pradler |
| Sculpted light nano and microsystems |
| Speaker: | Halina Rubinsztein-Dunlop (The University of Queensland, Australia) |
| Abstract: | Sculpted light refers to the generation of custom designed light fields. These light fields can be applied in many diverse fields ranging from interrogating single atoms or atom assembly to using these fields for optical micromanipulation and optical tweezers as well as creating new quantum devices and sensors. We consider here the study and application of light with structured intensity, polarization and phase. We can create custom fields in multiple planes using dynamic and geometric phase control. Sculpted light can be generated using spatial light modulators (SLM) or digital micromirror devices (DMD) and enable the production of configurable and flexible confining potentials at the nano and micron-scale. This results in production of highly configurable time-averaged traps. All these methods achieve dynamical and flexible sculpted light fields and enable imaging of the amplitude patt |
| Date: | Thu, 11.05.2023 |
| Time: | 10:30 |
| Duration: | 45 min |
| Location: | Hörsaal ATI |
| Contact: | Jörg Schmiedmayer |
| Stability of Classical Chromodynamic fields |
| Speaker: | Sylwia Bazak (Jan Kochanowski University of Kielce, Poland) |
| Abstract: | At the earliest phase of relativistic heavy-ion collisions there is generated a system of gluon fields which can be treated as classical. Numerical simulations show that the system is unstable but a character of the instability is not well understood. We perform a stability analysis of the initial chromoelectric and chromomagnetic fields which are parallel to the beam direction. While a configuration of the chromoelectric field is essentially Abelian with the single-color potential linearly depending on coordinates, the chromomagnetic is genuinely nonAbelian generated by the multicolor noncommuting potential components. We derive a spectrum of small fluctuations around the background fields which obey the linearized Yang-Mills equations and we argue that the nonAbelian chromomagnetic field is mostly responsible for the system's instability. |
| Date: | Thu, 11.05.2023 |
| Time: | 15:00 |
| Duration: | 60 min |
| Location: | TU Wien, Freihaus, Seminar room 10th floor; Zoom: Meeting ID: 950 0240 9522, Password: please ask via e-mail |
| Contact: | Kirill Boguslavski, Iva Lovrekovic |
| Speaker: | Zoran Hadzibabic (University of Cambridge) |
| Abstract: | For nearly three decades ultracold atomic gases have been used with great success to study fundamental many-body phenomena such as Bose-Einstein condensation and superfluidity. While traditionally they were produced in harmonic electromagnetic traps and thus had inhomogeneous densities, it is now also possible to create homogeneous samples in the uniform potential of an optical box trap [1]. Box trapping simplifies the interpretation of experimental results, provides more direct connections with theory and, in some cases, allows qualitatively new, hitherto impossible experiments. I will give an overview of our recent experiments with box-trapped three- and two-dimensional Bose gases, focusing on a series of related experiments on far-from-equilibrium phenomena, including turbulence [2-4] and dynamic scaling in driven disordered gases [5].
[1] Quantum gases in optical boxes (review), N. |
| Date: | Fri, 12.05.2023 |
| Time: | 10:00 |
| Duration: | 45 min |
| Location: | ATI Hörsaal/https://tuwien.zoom.us/j/93672218922?pwd=dEZNQ2liVzRNNURvNmVWVE5KUWRiQT09 |
| Contact: | Jörg Schmiedmayer |
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